title: Non-extraction HPLC method for simultaneous measurement of dyphylline and doxofylline in serum.
abstract: A direct injection HPLC method for the simultaneous measurement of dyphylline and doxofylline in serum is reported. Chromatography is carried out with a "Pinkerton" internal surface reversed-phase column and phosphate buffer (0.1 mol/L, pH 6.8) as mobile phase. Absorbance at 275 nm is monitored. Only 10 microL of serum is required to detect less than 1 mg of each drug per liter in biological samples. The standard curve for the method is linear over the range 6-100 mg/L, and precision is acceptable for both drugs, with CVs of 2% and 1.5% for respective concentrations of 6.2 and 25 mg/L. None of the 76 drugs tested for interference affected the measurement of either drug. Four samples can be injected per hour. This method provides a fast, accurate way to monitor two interesting therapeutic agents used in chronic obstructive airway diseases.
authors.affiliation: Institute of Forensic Medicine, University of Verona, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Tagliaro
authors.forename: R
authors.initials: R
authors.lastname: Dorizzi
authors.forename: A
authors.initials: A
authors.lastname: Frigerio
authors.forename: M
authors.initials: M
authors.lastname: Marigo
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004400:Dyphylline / Q000097:blood*; D006801:Humans; D007202:Indicators and Reagents; D008991:Monitoring, Physiologic; D013806:Theophylline / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D007202:Indicators and Reagents; D004400:Dyphylline; D013806:Theophylline; C029797:doxofylline